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The trio of biotechs were in investors' good graces today.

What: On Tuesday, at 2:50 p.m. EST bluebird bio(NASDAQ:BLUE), Juno Therapeutics(NASDAQ:JUNO), and Alnylam Pharmaceuticals(NASDAQ:ALNY) were up 10%, 7.6%, and 7.5% respectively. The only obvious connection between the three is that they're all biotechs without any products on the market -- none have any obvious news that justifies their moves. The broader NASDAQ Biotechnology Index is up Tuesday as well, albeit not as much as these lucky companies.

So what: Don't like the red that your development-stage biotech is experiencing? In this market, you just have to wait a few days, and there's a good chance that stock will have a big move in the other direction.

The moves on sentiment can be nauseous. And unfortunately there's been more down days than up days this year.

Now what: While the chart, might look like bluebird bio, Juno, and Alnylam have hit bottom, it's hard to know when this rollercoaster ride is going to end.

Assuming we're in for a few more gyrations up and down, investors have two choices: They can try to time the peaks and valleys with their buys and sells, or they can just ignore it and hold through the volatility. All three biotechs are scheduled to release clinical trial data this year, which should cause the companies' shares to trade on fundamentals rather than sentiment -- at least for a day or two.

Brian Orelli has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Alnylam Pharmaceuticals. The Motley Fool recommends bluebird bio and Juno Therapeutics. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.